Slice your sirloin as thin as you can. Set into mixing bowl and add spices, oil, soy sauce, ginger paste, rice vinegar, stir well. Marinate sirloin in refrigerator while you prepare your vegetables.
Clean bok choy and slice stalks in half leaving the leaf with substantial amount of stalk. If you don't like as much stalk cut the lower half off and slice into smaller pieces. Slice basil into long strings horizontally. I like to roll several basil leaves together (looks like a green bean) and slice horizontally. Slice red bell pepper and onions into long pieces. Chop cilantro and garlic I like my garlic in slivers but you can dice or chop add all veggies to mixing bowl. You can substitute any veggies you like.
Get your wok or large pan really hot a medium high heat is great. You really want to sear the meat with flavor. All the oils and seasoning should be soaked into the meat by now marinate longer if you like. Once the pan is very hot add beef until seared. Reduce heat after about 5-7 minutes and add veggies, cook for another 5 minutes or until done. You should have a very aromatic meal that has a kick.